Whats is going on with my ESC?

[westers47]

I just got done scratch building a modified 70% scale ft-22. I have a suppo 1806 2660kv motor with a 10amp suppo ESC that has a 1amp linear BEC and I am powering it with a 2s 500mah lipo.

I calibrated the ESC for mode 1 which is for a LiPo setup. The problem I am running into is when I try to use the control surfaces the motor dies and goes back into programming mode. I don't know if the ESC is bad or if this is a brown out. The BEC only has to push two 6gram servos.

Here are some pics of my build.

 

[Spastickitten]

Great build! Looks amazing! I might make one of these! I think it is a brown out, does the motor run fine without servos plugged in?

 

[westers47]

Thank you sir. I have not tried unplugging the servos but the motor does run fine until I active the servos and then the motor abruptly stops.

 

[Spastickitten]

Then the esc reboots? I think thats a brown out

 

[quorneng]

Your set up will be working a 500mAh battery quite hard. Do you have another preferably larger capacity battery you could try? If this cures the problem it proves the battery not the ESC is the problem.
The 1A BEC should be quite adequate providing the servo linkage and control surface hinges are really free moving.

 

[westers47]

I have a 3000kv 1306 that should be arriving soon. Perhaps swapping to this motor would this issue?

 

[Spastickitten]

No, changing the motor doesn't affect the output to the receiver/servos. The esc just has an internal BEC that regulates voltage for the receiver/servos.

 

[Spastickitten]

I would like to know where you got the plans for this plane though

 

[westers47]

I have used the same ESC with a smaller motor and was able to push 3 servos. I sounds like my current battery cant push enough power out for the 1806 and servos at the same time thus causing a brown out.

As for plans, everything but the fuselage is just scaled down FT-22 plans. I just made my own design for the fuselage so that I could incorporate a 10mm CF tube for reinforcement. I have a tendency to nose dive my planes into the ground.

 

[quorneng]

A watt meter would of course tell you what is really going on.

 

[Spastickitten]

Yes, a watt meter would help! ^w^

 

[Danyaal79]

To me as a noob i feel that 1) the battery is a bit small, try a 2s 1200 mah? 2) does the motor run w/o servos / control surface elctronics?

 

[ZoomNBoom]

I have used the same ESC with a smaller motor and was able to push 3 servos. I sounds like my current battery cant push enough power out for the 1806 and servos at the same time thus causing a brown out.

The BEC and the brushless controller part of the ESC are pretty much independent. Whats more likely is that you have stiffer hinges on this model, making the servo's work harder, and thus draw more current. If so, be happy you found out this way, and it didnt brown out in the air at full speed/full deflection.

 

[srfnmnk]

def sounds like you're over working the BEC...

I also feel like your 500 MAH 2S is quite small for that large a motor...i would suggest getting a larger BEC, a larger ESC with an internal BEC that provides more Amp out (in case your hinges are stiffer or linkages are longer) or just getting an external BEC.

 

[pressalltheknobs]

500 or 1200 mAH should not matter. That just says how long it will run. What may matter is the C rating of the battery although I doubt that's the problem.

More likely the battery is bad or not balanced. Have you checked the voltage? Is is balanced properly. Could be dangerous if it's not. Check this if you haven't.

Assuming the battery is good, possibly the 1 amp linear BEC cannot provide enough power for the servos driving those control surfaces. The way to check is to disconnect one of the servos from the receiver and see of the other one then works fine. Double check by switching to the other. Could be you have a bad servo and it's drawing more current than it should for some reason.

Also check for binding in the rods and linkages. Looks like a straight shot but there might be something that's binding up and causing a servo to stall. If you have adjustable linkages you can also loosen them and see of the servos work fine without the control surface load. Stiff hinges was a good suggestion.

 

[westers47]

I have checked my hinges and there is zero binding. I have tried using each servo by itself and the power cuts every time I activate a servo. The motor does run fine with out the servos connected. I have also checked the battery and the balance was fine. I did try another battery also.

At this point it has to be a bad esc. Going to see if I can dig one up or steel one from another scratch build.

 

[ika]

I was wrestling with this very same issue today with my brand new Suppo 10A ESC. My setup:
Scratch built FT Mini Scout airframe
2 x HXT500 5 gram servos
Suppo 2204/14 Brushless motor
Turnigy 8ch receiver
Turnigy 3s 500mAh Lipo battery
Turnigy 9x

The problem hit during the maiden flight, the ESC would just shut off the motor and down came the Mini Scout.

What was happening is the ESC would reset after moving the control surfaces. Since at this point the throttle stick was not at zero, the ESC would "safely" not turn the motor on. I took the wreck back to the workbench and sure enough, I could get the ESC to reset very reliably after moving the Rudder & Elevator a few times. I disconnected one servo and the resetting happened a bit less often. I tried TG9e (9g Turnigy servos) as well, same problem. I tried bigger battery, no help.

After searching all sorts of RC forums for a hint how to fix this, I happened upon a thread in an RC car forum where it was suggested that noise & high instantaneous current draw from servos could be the culprit, and to use a "glitch buster" to fix the issue.

A "glitch buster" is but a large capacitor installed across the power & ground in one of the servo outputs of the receiver. I made one myself out of a 1000uF / 16 V electrolytic capacitor, plugged it in and the problem was gone. You can find instructions to build & install one easily on youtube, or you can buy one online.

I just came back in from the 2nd maidening of my FT Mini Scout, and I couldn't be happier. It flew very nicely. I tried it with the 500mAh battery, and it could fly really slow. It was also able to carry a 1000mAh 3s battery, and even slightly nose heavy, it flew exceptionally. Thank you Flite Test for a wonderful design!

I hope this helps!

 

[ZoomNBoom]

If the BEC in you ESC is that marginal, I would not use it with or without 'glitchbuster'. Just add a separate ubec

 

[quorneng]

I would be very cautious using 9g servos with a 10A ESC as it is will most likely only have a 1A BEC.
As you have found a 9g servo can draw quite a significant instantaneous current. This overloads the BEC which drops the voltage to the radio which then cuts the signal to the ESC and down you come!

The glitchbuster capacitor is simply acting as a 'smoothing' battery to assist with short high current demands but big capacitors can also produce unwanted voltage 'spikes' which would do the delicate electronics no good at all.

If we assume the 10A ESC is suitable for the plane then it must be must be pretty small and light so do you really need anything like 9g servos? IMHO a 3.7g servo would be quite sufficient and they only draw 1/3A even when they are stalled!
With such micro servos a 1A BEC is now quite adequate.

In truth the BEC part of an ESC is by far the most critical part. Loose motor power and you can still glide to land. Loose the BEC and you are no longer in control of anything.

 

[ika]

I my particular build, the servos are 5g HXT500's and the Suppo 10A ESC I got actually has a 2A BEC and the servos are free moving. So the BEC is hardly marginal. The OP stated he has 6g servos (also free moving) but with a Suppo 10A ESC w/ 1A BEC. So the ESC rebooting is still a bit of a mystery.

> big capacitors can also produce unwanted voltage 'spikes' which would do the delicate electronics no good at all.
I'm not buying this. The only way you would get a voltage spike from the cap would be if you charge the cap 1st to a high voltage, then insert it into your receiver.